Refrigerant evaporator, improved for uniform temperature of air blown out therefrom

Abstract

According to the present invention, plural downstream side evaporation passages in a downstream side heat exchanging unit are divided into two groups substantially at the middle of the width by a separator, plural upstream side evaporation passages in an upstream side heat exchanging unit are divided into two groups substantially at the middle of the width by a separator, and a downstream side lower tank and an upstream side upper tank are communicated by a communication passage so that inefficient heat exchanging areas of the downstream side heat exchanging unit and the upstream side heat exchanging unit disposed one after the other with respect to the flowing direction of air may not overlap with each other. Since the inefficient heat exchanging area in the downstream side heat exchanging unit and the inefficient area in the upstream side heat exchanging unit are disposed symmetrically with each other, the temperature distribution of air blown out from the refrigerant evaporator is prevented from being biased, and air having a uniform temperature distribution can be produced by the refrigerant evaporator.

What is claimed is: 
     
       1. A refrigerant evaporator for evaporating refrigerant flowing therein so as to cool outside air flowing therethrough, comprising: first evaporation passage means for defining plural first evaporation passages through which the refrigerant flows, said plural first evaporation passages being formed vertically and arranged substantially in parallel with each other in a direction substantially perpendicular to the flowing direction of said outside air;   a first tank portion connected to each of upper ends and lower ends of said plural first evaporation passages, said first tank portion being extended in a direction crossing said first evaporation passages;   second evaporation passage means for defining plural second evaporation passages through which the refrigerant flows, said plural second evaporation passages being formed vertically and arranged substantially in parallel with each other in a direction substantially perpendicular to the flowing direction of said outside air, said plural second evaporation passages being disposed adjacent to said first evaporation passages at a downstream side of said first evaporation passages with respect to the flowing direction of said outside air;   a second tank portion connected to each of upper ends and lower ends of said plural second evaporation passages, and said second tank portion being extended in a direction crossing said second evaporation passages; and   communication means for defining a communication passage for communicating between said plural first evaporation passages and said plural second evaporation passage;   wherein the refrigerant flows in the same vertical direction at least in portions where said plural first evaporation passages and said plural second evaporation passages overlap with each other with respect to the flowing direction of the outside air, and the flowing direction of the refrigerant in said first tank portion connected to said first evaporation passages and that in said second tank portion connected to said second evaporation passages are opposite to each other.   
     
     
       2. A refrigerant evaporator according to claim 1, wherein, said first tank portion includes a first upper tank connected to each of said upper ends of said first evaporation passages, and a first lower tank connected to each of said lower ends of said first evaporation passages; and   said second tank portion includes a second upper tank connected to each of said upper ends of said second evaporation passages, and a second lower tank connected to each of said lower ends of said second evaporation passages.   
     
     
       3. A refrigerant evaporator according to claim 2, wherein, said second lower tank includes a refrigerant inlet at one end thereof,   said first upper tank includes a refrigerant outlet at one end thereof, and   refrigerant introduced through said refrigerant inlet into said second lower tank flows upward through all of said second evaporation passages, flows from said second upper tank through said communication passage into said first lower tank, flows upward through said first evaporation passages, and then flows outside through said refrigerant outlet.   
     
     
       4. A refrigerant evaporator according to claim 2, further comprising: a first partition member for partitioning an interior of said first upper tank into plural sections; and   a second partition member for partitioning an interior of said second lower tank into plural sections.   
     
     
       5. A refrigerant evaporator according to claim 4, wherein the number of said sections of said first upper tank partitioned by said first partition member is equal to that of said second lower tank partitioned by said second partition member. 
     
     
       6. A refrigerant evaporator according to claim 5, wherein each interior of said first upper tank and said second lower tank is partitioned into two sections. 
     
     
       7. A refrigerant evaporator according to claim 5, wherein each interior of said first upper tank and said second lower tank is divided into two sections, and each interior of said first lower tank and said second upper tank is divided into two sections. 
     
     
       8. A refrigerant evaporator according to claim 5, wherein each interior of said first upper tank and said second lower tank is divided into three sections, and each interior of said first lower tank and said second upper tank is divided into two sections. 
     
     
       9. A refrigerant evaporator according to claim 5, wherein, said second lower tank includes a refrigerant inlet at one end thereof;   said first upper tank includes a refrigerant outlet at one end thereof; and   the other end of said second lower tank and the other end of said first upper tank are communicated by said communication passage.   
     
     
       10. A refrigerant evaporator according to claim 1, wherein, each of said plural first evaporation passages overlaps with each of said plural second evaporation passages overlap with respect to the flowing direction of the outside air, and   each pair of directions of the refrigerant flowing vertically in said first evaporation passage and said second evaporation passage, which overlap with each other, are the same.   
     
     
       11. A refrigerant evaporator according to claim 4, wherein said first evaporation passages are divided into an even number of evaporation passage groups, and said second evaporation passages are divided into an odd number of evaporation passage groups.